Attorney General Jeff Sessions indicated that the reaction to President Trump's condemnation of the "many sides" of violence in Charlottesville are overblown on Aug. 14, saying, "We will not tolerate this kind of hatred and violence." (Reuters)

Since a car bulldozed through counterprotesters Saturday, questions have swirled about whether the attack was a hate crime, terrorism or both, a determination that could impact whether federal charges follow a local prosecution in Virginia.

The Justice Department launched a civil rights investigation into the incident, which Sessions on Monday called “an unequivocally unacceptable and evil attack.” Sessions has also vowed that federal authorities will seek “the most serious charges that can be brought.”

While Fields has long sympathized with Nazi views, former federal prosecutors and investigators said his background did not necessarily mean he will face federal hate-crime charges because that depends on what officials conclude might have motivated him.

“If you’re a racist and you kill someone, that doesn’t mean it’s a hate crime,” said Timothy J. Heaphy, a former U.S. attorney in the Western District of Virginia, which encompasses Charlottesville. “There has to be an explicit connection between the two for it to be a civil rights offense.”

Investigators will coordinate with local prosecutors to try to find any “linkage between the ideology and the criminal act,” said Heaphy, who lives in Charlottesville. Such an investigation will include poring over Fields’s history and social media accounts as well as interviewing people who know him. “Was this an impulsive act, or was it more intentionally directed at a particular group?”

Bill Nettles, the former U.S. attorney in South Carolina, said what could tilt any federal prosecution toward domestic terrorism vs. a hate crime would be whether investigators determine Fields was angry because of the counterprotesters and decided to ram them rather than specifically going after a group covered under hate-crimes law.

“For something to be a hate crime, it has to be more than you hate somebody,” Nettles said. “It’s got to be you hate somebody that is one of the groups of people, the narrowly defined groups of people, contained in the hate crimes statute.”

Terrorism, by comparison, would entail someone becoming enraged by counterprotesters and using their car as a weapon against them, Nettles said.

“The point of terrorism is to spread fear,” he said. “The point of a hate crime is to inflict hate on one of the specific groups that is narrowly defined in the statute.”

A memorial at the site of the deadly car attack in Charlottesville. (Evelyn Hockstein for The Washington Post)

Nettles said he agreed with Sessions that based on information available so far, the attack would appear to be domestic terrorism, adding that the investigation could also determine that it was both a terrorist attack and a hate crime.

The investigation could also find that the attack was meant to send a specific message, because a key part of terrorism is trying to send a message, said David Gomez, a former FBI counterterrorism official and Los Angeles police officer.

“It goes back to motivation,” Gomez said. “Either way, a hate crime in court, a prosecutor has to prove motivation, and for terrorism, he has to prove motivation. So for the investigator, they say, ‘How do I prove that?’ ”

Two days after a woman was killed in Charlottesville amid clashes between white nationalists and counterprotesters, President Trump on Aug. 14 condemned racist groups such as the KKK, saying racism "has no place in America." (The Washington Post)

The Justice Department has had counterterrorism prosecutors and FBI counterterrorism agents involved in the case since Saturday, according to a spokeswoman. The FBI, Civil Rights Division and U.S. Attorney’s Office for the Western District of Virginia opened the civil rights probe into “the deadly vehicular incident” in Charlottesville on Saturday, federal officials said in a statement.

Labeling an attack as domestic terrorism can give the federal government increased authority to investigate what happened, as Susan Hennessey, a former attorney at the National Security Agency, wrote for Lawrfare in 2015.

Whether any potential federal charges following the Charlottesville attack could mention domestic terrorism is another question. While domestic terrorism is defined federally as something aimed at intimidating a civilian population or trying to influence government policy, Sarah Isgur Flores, the Justice Department spokeswoman, noted Monday that there is no specific federal charge for domestic terror.

“It matters a lot for public confidence in government and our ability to respond to attacks like this,” Heaphy said. “If this is domestic terrorism, if this is hate based, it has to be called out as such.”

He added: “It may not make a difference for the number of days this person may spend incarcerated, but it makes a huge difference for … our ability to hold people accountable for what they did.”

Some domestic terrorism probes have led to other types of charges that carry criminal penalties. Last year in Kansas, after the FBI conducted a domestic terrorism investigation of a militia group, federal authorities charged three men they said were plotting attacks on Muslim immigrants with conspiring to use a weapon of mass destruction. That charge came because the men plotted to bomb an apartment complex that housed a mosque and Somali people, officials said.

After some cases, including the Charleston, S.C., church massacre in 2015, questions have swirled regarding what federal authorities will and will not describe as terrorism.

“The line between a hate crime and terrorism would fall into this space of, is there a political motive?” said J.M. Berger, a fellow with the International Center for Counter-Terrorism at The Hague who studies extremism and terrorism.

Berger said it has long been an issue that there has not been an objective standard for examining and categorizing extremist threats and behaviors.

“The major problem we have in this realm is that there’s a de facto assumption that when a Muslim does it, it’s terrorism,” Berger said Monday, describing the way extremist attacks and plots are characterized. “And when a white guy does it, it’s mental illness or something else. Unsurprisingly, reality is more complicated than the categories we create for these things.”

Berger said the Charlottesville violence could be a tipping point in the discussion about what is labeled terrorism, saying that there “is a critical mass of both officials and people in the public referring to this attack as terrorism.” He noted that this includes politicians calling the attack terrorism who might not have done that before.

A part of how federal authorities proceed in Charlottesville might focus on what the Justice Department wants to say to the public about what happened, said Nettles, the former federal prosecutor who was involved in the Dylann Roof prosecution in Charleston before resigning last year. He said charging decisions by prosecutors in cases like this are meant to punish the person who committed the crime.

“But in cases like this, you do want to send a message to the community,” Nettles said.